My current strategy is to burn OS 2008 onto an SD card and boot off of that. Then scp the data off.
I have "RX-34_DIABLO_5.2008.43-7_PR_COMBINED_MR0_ARM.bin," which I am intending to burn, as well as flasher-3.5. However the flags for flasher don't seem to support burning onto another SD card. Or if there is another way to burn it onto the sd card that would be great.

I have Mac, Linux and Windows. So I no platform issues should be of concern.

any steps or suggestions?

I am not sure what you are trying to do, but if you want to boot from SD then just install pbeasy (search the forum). It has easy tools to partition, format, clone and flash boot menu.